85ESL73M motor height

[ronward]

I've read all kinds of posts on here that say the anti-cav plate should be even or maybe 1/2" above bottom of keel. I just mounted the motor today and have it 1/2" above keel. Then it occurred to me that the tips of my prop are only 1/2" away from the bottom of anti-cav plate. Now if that plate is supposed to be even with the water or actually out of the water when planed, wouldn't the prop be too close to the surface? I'm dying to lower the motor but if the general consensus says not to then I'll try it like it is.

 

[oldboat1]

Re: 85ESL73M motor height

rule of thumb for vent plate is one inch above to one inch below the bottom of the boat (not the keel). It sounds like you are virtually even with the bottom of the boat, so should be fine. If the motor is up and running, try the rig out and see how it performs.

 

[boobie]

Re: 85ESL73M motor height

Go run it. It sounds okay.

 

[ronward]

Re: 85ESL73M motor height

Here is a pic if it will work.

 

[racerone]

Re: 85ESL73M motor height

The vertical height of the transom should be 20 "

 

[F_R]

Re: 85ESL73M motor height

The object of the game is to run it as high as you can without experiencing excessive cavitation or ventilation. If it does, lower it a notch. Race motors often run with the whole top half of the prop above water. Runs like a striped ape once you get it going, but won't get out of it's own way at take-off.

 

[MikDee]

Re: 85ESL73M motor height

You should be fine, as long as your water intake holes on the lower part of the leg are in the water.

 

[emdsapmgr]

Re: 85ESL73M motor height

Hard to tell just where to mount it when it's on the trailer. You need to check it when it's running on plane and trimmed all the way back. The water flowing from under the boat should run just under the lower unit's anti-ventilation plate-with an aluminum prop. If that plate is buried under water, you'll get spray and lots of drag-poor performance. If you run a stainless prop, you can start to raise the engine even higher. The stainless props will run with some of the blade out of the water- and still maintain bite. (make sure you don't run it out of the water so far that the engine loses water pressure.) FR has given a nice explanation, #6, above.

 

[ronward]

Re: 85ESL73M motor height

What I'm trying to find out, from thr experts, is if the setup in the pic looks like a good strarting point or should I go a little lower before I seal it all up. I AM running a SS prop which should gain me a little height but I would like more experienced opinions

 

[emdsapmgr]

Re: 85ESL73M motor height

The way you have it mounted should be good for an initial test run. Appears that at WOT, all of the water intake holes will be underwater-that's good. I understand your concern for water pressure, since this older engine does not have a telltale.

 

[ronward]

Re: 85ESL73M motor height

That brings me to another question about installing a tell tale but I'll start a new thread. Thanks for your reply

 

[emdsapmgr]

Re: 85ESL73M motor height

One easy way to add a telltale is to replace the outer exhaust cover with a used (from a 1978 and up) cover. It will already have the hole for the hose barb. Must be literally hundreds of these old covers around in garages and salvage yards.

 

[V153]

Re: 85ESL73M motor height

Handy chart:

Fwiw I run 2" above.